1. Field of the Invention
The present invention relates to a plasma monitoring method, a plasma processing apparatus and a plasma processing method, and more specifically, it relates to a plasma leak monitoring method, a plasma processing apparatus and a plasma processing method which make it possible to quickly detect a plasma leak occurring during a plasma processing.
2. Description of the Related Art
Semiconductors are manufactured by utilizing various types of manufacturing apparatuses and inspection apparatuses under diverse conditions. In particular, a plasma processing apparatus is sometimes utilized to execute processing by setting the pressure of the process gas inside the processing container to a relatively high level and also setting the high-frequency power that is applied to a high level so as to raise the density of the plasma being excited, as a way of enabling production of a semiconductor achieving higher integration and higher density.
When executing processing with such high density plasma, the plasma cannot be trapped at the top of the workpiece with a high degree of efficiency if a part such as an evacuation ring provided around the lower electrode which also functions as a workpiece stage is not mounted securely inside the plasma processing apparatus to result in a so-called plasma leak in which the plasma leaks out to another area such as a space under the evacuation ring. Since, in the event of a plasma leak, some workpieces may not be processed correctly even under processing conditions that are otherwise consistent, a problem arises in that the yield of the semiconductor production becomes poor.
Plasma processing apparatuses in the related art, which do not include a means for detection capable of detecting a plasma leak accurately, are not easily able to accurately determine whether not an abnormal workpiece processing state has been caused by a plasma leak and thus cannot correctly adjust the plasma processing apparatus state and the processing conditions.
An object of the present invention, which has been completed by addressing the problem of the plasma leak monitoring method and the plasma processing apparatuses in the related art, is to provide a new and improved plasma leak monitoring method, a new and improved plasma processing apparatus and a new and improved plasma processing method that make it possible to accurately and reliably detect a plasma leak.